Steam-superheater.



E. H. POSTER & 'J. PRIMROSE. STEAM SUPERHEATER. APPLICATION FILED JAN. a, 190e.

Patented Nov. 2, 1909 I y @Z713 :their @Miou/w16:

UNITED sTATEs PATENT oEEioE.

ERNEST VH. FOSTER AND roi-1N ranvmosn, or NEW YORK, N. Y. I

l STEAM-SUPEEHEATER.

of steam, more particularly in connection` with so-called re-tube boilers.

In generators `of this type it is usually most convenient to locate the superheater at the point where the furnace gases leave the l lire-tubes or boiler iiues, but by the time the part of their heat gases have reached this point they have given up ,so much of their heatvto the boiler that a very large superheating surface is necessary in order to obtain the desired degree of superheat. Not infrequently the temperature of the gasesissuing from the lues is even below this desired temperature and the steam therefore cannot be superheated at all.

Toremedy this defect, so that furnace gases sufficiently hot can at all times be supplied to the superheater, is the chief lobject of our invention. V

lVe have also devised a novel form and arrangement of superheater, for use lmore especially withA boilers of the kind mentioned, which possesses a high degree of efficiency. L

In carrying-out our invention in its preferred form, we provide a suitable number of iiues for conveying hot gases to the superheater, which is located in the smoke-box between the boiler and the stack, and in order to prevent the gases, while liowing through theseziues, giving up too' large a y to the contents of the boiler,l the iiiies may be insulated. .We prefer to secure the desired insulation by inclo ingfthese flues in some-manner which wf keep the water in the boiler out of conta'cff'with the iues at least ,for the greater part of their'length. A convenient method for this"p1irp,ose,`in the case of iiues which are-located, below the normal water level, is

to provide each with a casing of somewhat larger diameter so asto leave an annular space between the two. By preference this specification of Letters Patent.

Patented Nav. a, ieee.y

Application led January 8,l 1906. Serial No. 295,095.

space is not packed, the body of air or steam therein giving suf'cient insulation.

The boiler iiues the smoke-boxv lat the end of the boiler, and in the smoke-box is located the superheater".

This consists preferably of two parts, one located at each side of the box, each consisting of a plurality of tubes connected to upper and lower headers. The upper headers are' connected with a pipe which is open to the steam space or to the steam dome of the; boiler and therefore carries steam to these` headers. The lower headers are to be connected with an outlet pipe by which the superheated steam may be delivered to the point of utilization. Bydividing the superheater into two Iseparated sections a clear space is left between them, aii'ording a free passage for the products of combustion to the stack. or iues which carry the highly` heated gases is one or more chambers or conduits to receive the gases and direct them eectively against the superheater elements.` 1n the conduit or conduits is one or more dampers, whereby the supply of-heated gases may be cut ofi or regulated at will. f In the annexedV drawing is illustrated the preferred embodiment of the invention.

Figure 1 is a vertical, longitudinal section showing a tire tube boiler equipped with our invention. Fig. 2 ,isla longitudinal section on line II-II, Fig. l.` Figs. 3 and 4 are discharge their gases intok At the discharge end of the flue y detail views, partly in section, showing the .y

insulating casing around the flue, with twoV methods of forming casing and lu'e. a

The boiler illustrated, indicated at l, is

the joint between the one of what is commonly known as the locomotive type, having a tube sheets 3 and 4, smoke box 5 tire box or furnace 2, at the front end of the boiler, and steam dome 6.

Extending between fthe tube sheets are the iues or ire tubes, indicated by 7, receiving the products of combustion from the furnace 2 and discharging them into the smoke-box A The superheater is constructed in two parts or sections. More strictly speaking` in thepresent instance the two parts constitute two superheaters, as will be seen presently.

Supported in any suitable manner at the top` of the smoke-box are two parallel heade'is; 8, 9, adjacent to each other and extending in line with the axis ofthe boiler. At the rear' end ot' the headers Vis a Y-pipe l0, extending to an opening in tube sheet l, and there connecting witha supply pipe ll which extends back and is open to the steam doineti, so that steam from the dome is carried to the upper headers. 12 and 13 indicate the sii'iierheater tubes which are connected to headers H and 9 respectively. 'lhese tubes extend to right and left from their respective headers; and',l

bending downward adjacent Vtothe sidesl ot' thesmokelbox, the'tubes extend to the bottom of the box, where they again bend, this time toward thecenter of the box, and are casss ranged directly below their respective upper or inlet headers. indicated at 14, in Fig-J l. header is provided with an outlet, as la,

which may 'be connected to a common steam propel' temperatureinain; or, as in the case of a locomotive. each lower header may bc'connected with the engine on its own side ofthe boiler. ln such case the two parts of the superheat er constitute in effect two substantially independent superhcaters.

Each superheater, or section thereof, is in-v closed in a heating chamber, preferably in the following manner, considering for convenience'only the chamber or casing on t he left, shown in Ilig: V1 as well as in Fig. 2.

This chamber' has a vertical wall 1G, which at `top and bottom has horizontal extensions,

not shown, reaching over to the upper and lower headers. The bottom of the chan'iber, indicated at 17, Fig. l, extends t'roiu the side wall of the smoke-box over to the lower header, and thus covers the lower horizontal portions of the tube 13. Extending about two-thirds of the way down from. the top of compartmentsl 19` 20.

theA chamber "is a transverse partition or baffle plate 18, dividing the. chamber into two The rear compartment, 19, is closed above the upper horizonkvtal portions of the pipes 13. as indicated at 21, Fig. l, while the front compartment. or conduit, 20, is open. lt will therefore be seen that the hot gases, it delivered into the upper part of the closed compartment. 19,

will flow downward, bathing the rear tubes,

then forward below the partition 1S and up l through the front compartment.y bathing the tubes therein and escapingcfrom theI open top into the smoke box, whence they, passito the stack above the opening 22. A

For the purpose of delivering highlg lient--` ed gases from the furnace to the sum-irheater chamber We provide special lines `or liretubes, as previously mentionethqpi'ejlerably located entiiely abcve the body ot tubes 7,1

as shown at 23. These ina \7 be otanv suitable size and as many maybe used as are necessary to deliver the desired amount ol hot gases. the special tubes. which for convenience ot' reference may be spoken of as the supert'orm of a tube of larger dian'ietei".f'.lhel air r heat of `the gases 'and they therefore reach'y the tlue exits .at the In order to keepthe ues and casings at all'tiniesdii Iconcentric positions relative to each other, thecasing may be provided with. inwardly projecting bosses or lugs,. vliich niay bepniade by stamp ing in the casing wall, as indicated at1`25, ligs. 3 and 4l.'v Asalready stated, the joints at the ends of the iues should bein contact with the water, to prevent overheatinfr. Hence the casings -do not extend thelfulll length of the lilies, butterininate short of the tube sheets at each end.` Itis of lcotirse desirable that the joints between the lues and casing be substantially liquidtight. A convenient way of foririingthese joints is to place on the liue a tightly litting collar 26, Fig. 3,jover whichl the casing fitsy closely and abuts against a flange 2.7 to prevent longitudinal displacement. Another convenient. method is to contract the end of the casing around the flue, as indicated at 28, Fig. 4.

For the purposeof conducting thehot' gases from the f iues to the superheating chambers, Without these gasesmingling `with the cooler products of combustion discharged by the boiler tubesv7, we provide a branched conduit 29, with its larger end `over the superheated tlues 2Q, the divergentA branches leadingto the upperparts of the rear coinpartinents of the right and left superheating chambers respectively. In this way the hot gases 1 are led directly against the super- `heater tubes, and in the passage of the gases throughtlie chambers. they at all times, are kept in close confinement around the tubes.. When the superheater sections are' practi cally independent, as above described, the

conduit is preferably vdivided by a ,partition extend-ing from the'A angle ofthe indicated by .the Y dotted line at `B0, ,Fig.:2. Each .half of the conduit provided with adampeigas 31, 32, pivot'edat-the'top and f actuated by an arm, as 325, 34, on shaftsextending outside the smoke-box. These arms may be connected with the engineers cab ln the construction illustrated. l

in any convenient way, not shoWn.- By closing one damper or the other the hot gases branches, as

cailllfb' out oli from either superheater at W1 *pmi-52j It will, of course, be understood that the construction herein specifically describedds merely the preferred form of the invention` which may be embodied in a considerablel variety of forms without departing from its proper scope as deined by ther following claims.

' What We claim as our invention is:

51.. The combination with-a steam boiler" having are-box, or furnace, and a smokebox, of two pairs of companion headers extending lengthwise of thesmoke-box, one member of each air being located in the upper part of the x near the center thereo and the other member of each pair being located near the bottom of the box, superheatiug tubes connecting the upper and lower headers respectively, inclosing chambers for the superheaters each chamber being pro- Y vided with a partition depending from its top wall of less length than the height of the chamber, and means for discharing hot Y ases from the upper.v row of fire-tu es into the'upper portionof the chamber in rear of said partition, the u per part of the front portion of said cham ers being in connnunication with the smoke outlet. 1

2. The combination with a steam boiler, havingpa lire box or furnace, nand a smoke box, of two pairs of companion headers extending lengthwise of the smoke box, one member `,of each pair being located in an up er part of the box near the center thereof and the other'member of each pair being located near the bottom of the box, superheating tubes connecting thernpper and lower headers respectively, inclbsing chambers for the superheaters, means within theehambers for causing the circuitous lgases therethrough, and means for discharging gases from the upper row of ire tubes into :the rear portion 4of the chambers, the front portion of said chambers being in communication with the smoke outlet.

ERNEST H. FGS'EER.

JOHN PRIMROSE.

' Witnesses: V

M. LAWSON Dyna, S. S. Dommia.

passage of hot' 

